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Journal of Chemical Sciences

, Volume 115, Issue 5–6, pp 637–647 | Cite as

Aromaticity in benzene-like rings — An experimental electron density investigation

  • Anupama Ranganathan
  • G. U. Kulkarni
Article

Abstract

An experimental charge density study has been carried out on perylene based on X-ray diffraction measurements at 130 K. The electron density and its associated properties have been evaluated at the bond and the ring critical points for the naphthalene residues as well as for the central ring. The variation of the Laplacian along the axis, above and below the ring plane, is found to be symmetric for the central ring while for the naphthalene rings, the Laplacian values are enhanced under the bow-shaped region. A plot of the Laplacian versus density evaluated at various points along the axis above the ring plane, shows a steep variation in the case of the central ring implying that theπ-density is smeared out compared to that over the naphthalene rings. Similar data extracted from a quinoid ring and a regular phenyl ring (both based on earlier reports from this laboratory) exhibit increasingly shallower trends and indicate, by contrast, that the central ring of perylene is much less aromatic.

Keywords

Perylene aromaticity experimental electron density 

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Copyright information

© Indian Academy of Sciences 2003

Authors and Affiliations

  1. 1.Chemistry and Physics of Materials UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBangaloreIndia

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